When it comes to the recent drive to adopt electric vehicles in India, a major problem that brands and the government have had to address is disseminating proper information and education. Electric vehicles are, in many ways, very different from ICE vehicles and these differences entail certain unique elements in the user experience. Before the mass adoption of electric vehicles in India, it is important for the Indian customer base to learn about these unique aspects of electric vehicles and understand their implications properly.
One such aspect that every potential electric vehicle owner has to wrap their head around is regenerative braking. With the way electric vehicles operate, regenerative braking is an extremely important concept that is closely linked with the driving experience of those who adopt electric vehicles. Since range and range anxiety are unavoidable parts of the electric vehicle conversation, the concept of regenerative braking is something that is particularly relevant to this conversation. Once you understand what regenerative braking is and how it works, it can become a lot easier to take a critical look at the electric vehicle options available in the market and choose the right model and features for your needs.
Let us take a look at regenerative braking from the ground up and discuss its most important aspects.
What is regenerative braking?
Braking a vehicle, during most of the time in the heyday of vehicles based on ICE technology, involved a waste of energy. Basically, braking is a maneuver where a moving vehicle is brought to a stop or slowed down as a controlled move by the driver. This is essentially a process of taking away the kinetic energy of a moving vehicle and transforming that into another form of energy. So far, this has been done through the application of friction.
When you apply the brakes in an ICE vehicle, brake pads physically press against the wheels, slowing them down due to friction. The kinetic energy of the vehicle is converted to heat energy due to the friction, which is wasted as the vehicle slows down. It also results in wear and tear of the brake pads over time. Regenerative braking, employed especially in electric vehicles of this day and age, makes use of the energy produced during braking in a constructive way.
In regenerative braking, the motor of an electric vehicle is used as a generator to convert the kinetic energy of the vehicle into electrical energy, which goes back into the car battery and gets stored away for future use. This is accomplished thanks to the fact that electric motors used in cars can move in both directions. While they move towards one direction while the vehicle is being driven, they start moving into the other direction the moment the brakes are applied, acting as a generator and generating electrical energy, which can then be put back into the battery.
Here, it is important to remember that the more braking force the driver applies, the more electricity can be generated. This makes it an incredibly useful technology in electric cars because of the usual range anxiety that is associated with their use. With regular car use, especially in start-stop city traffic, regenerative braking can actually top the battery up quite a bit, extending the range of the vehicle and allowing drivers more time between battery charges.
Implementation in electric vehicles
In the case of electric vehicles, regenerative braking is integrated into the control system of the car in a couple of different ways:
- When the brakes are applied, the motor reverses direction and the braking power is used to convert the kinetic energy of the slowing vehicle into electrical energy to be stored back in the battery. This is analogous to the friction-based braking of ICE vehicles.
- Regenerative braking is also sometimes engaged in electric vehicles when a driver takes their foot off the throttle. In such systems, it is often possible for the driver to choose between different levels of regenerative braking that would be applied. A good parallel for this in the ICE domain is engine braking, where a driver would gradually lower the gear ratio of the engine to slow the vehicle down.
Keeping these two situations in mind, it can safely be said that the driving behavior of the driver and the driving conditions at large play a major role in determining the total amount of energy that can be recouped and stored back in the battery. However, it is general consensus that regenerative braking can help improve range and dramatically avoid wasting energy in any form during driving.
At the current state of development, studies indicate that in regular city commutes with occasional highway driving, regenerative braking can add as much as 10-15% to the range of the car. However, under ideal conditions like extended downhill driving, regenerative braking alone can add up to 50% to the range of the car. This is a testament to the effectiveness and utility of the technology.
It is also important to remember that while no system is 100% efficient, there have been incremental improvements to regenerative braking technology over the years. With each passing year, electric vehicle manufactures are coming up with more complex, sophisticated versions of the technology with improved efficiency of recapturing power. The latest systems can often recoup about 70% of the energy generated from braking and transform it back into electrical energy to add to the battery.
Some disadvantages
While regenerative braking is altogether an exciting technology that makes the process of owning an electric vehicle more enjoyable, there are some drawbacks you need to watch out for so that you have the entire picture in mind before planning.
The first drawback is the lack of effectiveness of regenerative braking to replenish the battery in low-speed driving. Coming to a stop or slowing down from higher speeds does a much better job of using regenerative braking technology. However, in low-speed traffic, the returns might be meager. This is further compounded by the fact that first generations of technology tend to be relatively inefficient. Unless you are driving a modern, recently released electric vehicle, you might not get much extra juice out of regenerative braking if your regular commute is slow.
Another drawback is the fact that in many regenerative braking systems, the fact that a different method of braking is being used can actually lessen your stopping power. Friction-based brakes, for all their inefficiency in wasted energy, actually provide a physical barrier to speed in terms of friction and usually have better-stopping power. With regenerative braking, you might have to use the brake pedal more liberally and forcefully to achieve the same effect.
Finally, the braking “feel” of a vehicle is substantially altered when it uses regenerative braking. Those accustomed to driving ICE vehicles might notice very different brake pedal behavior, including mushiness and momentary unresponsiveness. Drivers may need to learn how much brake to apply and how to modulate the brake afresh in order to achieve the same standards of smooth, clean, and jerk-free braking using regen.
Key takeaways
With these important things in mind, it is easy to see why regenerative braking is a crucial technology to have in electric vehicles. Those looking to adopt electric vehicles in India will surely hope that more and more manufactures use this technology in electric vehicles available in India and the technology gets even better with time.
